Hello i am gonna battle my friend in pokemon emerald soon and i need some help with the setup my pokemons are Alakazam lvl 58 Salamance lvl 60 shedinja lvl 54 kingdra lvl54 dusklops lvl50 and a linoone lvl 46 im meeting a aggron ludicolo sceptyle manetric swellow and a torchoal all lvl 57 what should be my setup what moves should i teach them (mod may move post if placed wrong)

As far as I see your is somewhat average for the levels of your team. If I was on your side, then I would at least train that Dusklops to lvl 60. If you have enough time, train them all above 60, that will help a lot.
I think with a team like that you could definitely kick his ass.